Fig. 1.

Serum APOE concentrations inversely correlate with inflammation in COVID-19 patients and APOE3 protein dose-dependently inhibits SARS-CoV-2 pseudo-virus infection. a–g Correlation between APOE and cytokine/chemokine concentrations in serum samples from COVID-19 patients after the adjustment for sex and age. n = 73. h–k Confocal imaging analysis (h–i) and flow cytometry (j–k) of VSV-ΔG-SARS-CoV-2-EGFP pseudo-viral load in 293T-ACE2 cells treated with varying concentrations of recombinant APOE3 proteins. n = 4 independent experiments. l–o Effect of APOE3 treatment on the transduction of SARS-CoV2 pseudo-virus in mouse lung expressing human ACE2. l Schematic of the study design. m qRT-PCR analysis of pseudo-viral EGFP mRNA levels in lung tissues. n = 3 mice per group. n–o Confocal image analysis of VSV-ΔG-SARS-CoV-2-EGFP pseudo-viral load in lung tissues. n = 4 mice per group. Data are presented as mean ± S.E.M. One-way ANOVA tests were used to determine statistical significance. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001